U.S. patent number 10,494,981 [Application Number 16/434,257] was granted by the patent office on 2019-12-03 for combustion pre-chamber device for an internal combustion engine.
This patent grant is currently assigned to Cummins Inc. The grantee listed for this patent is Cummins Inc.. Invention is credited to Akintomide K. Akinola, Dwight A. Doig, Rick Vaughan Lewis, Jr., Andrew P. Perr, Philipe F. Saad.
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United States Patent |
10,494,981 |
Perr , et al. |
December 3, 2019 |
Combustion pre-chamber device for an internal combustion engine
Abstract
A combustion pre-chamber device for a spark ignition internal
combustion engine is configured to engage a spark plug and be
mounted to a cylinder head in communication with a combustion
chamber of a cylinder of the engine. The combustion pre-chamber
device includes a number of bores that open at an outer surface
thereof that extend into the body and receive a coolant flow to
provide cooling for a combustion pre-chamber of the combustion
pre-chamber device.
Inventors: |
Perr; Andrew P. (Columbus,
IN), Saad; Philipe F. (Columbus, IN), Akinola; Akintomide
K. (Whiteland, IN), Lewis, Jr.; Rick Vaughan (Franklin,
IN), Doig; Dwight A. (Columbus, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Cummins Inc. |
Columbus |
IN |
US |
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Assignee: |
Cummins Inc (Columbus,
IN)
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Family
ID: |
62491566 |
Appl.
No.: |
16/434,257 |
Filed: |
June 7, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190284985 A1 |
Sep 19, 2019 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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PCT/US2017/065032 |
Dec 7, 2017 |
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62431872 |
Dec 9, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02P
13/00 (20130101); H01T 13/54 (20130101); F02M
21/0275 (20130101); F02B 19/18 (20130101); F02B
19/10 (20130101); F01P 3/02 (20130101); F02B
19/1009 (20130101); F02B 19/12 (20130101); F02B
19/16 (20130101); F01P 3/16 (20130101); F01P
2003/024 (20130101); F02M 21/0203 (20130101) |
Current International
Class: |
F01P
3/16 (20060101); F02P 13/00 (20060101); F02B
19/10 (20060101); F02B 19/12 (20060101); H01T
13/54 (20060101); F02B 19/18 (20060101); F01P
3/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Search Report and Written Opinion, PCT Appln. No.
PCT/US2017/065032, dated Feb. 9, 2018, 7 pgs. cited by
applicant.
|
Primary Examiner: Amick; Jacob M
Attorney, Agent or Firm: Taft Stettinius & Hollister
LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation of International Patent
Application No. PCT/US17/65032 filed on Dec. 7, 2017, which claims
the benefit of the filing date of U.S. Provisional App. Ser. No.
62/431,872 filed on Dec. 9, 2016, each of which is incorporated
herein by reference.
Claims
What is claimed is:
1. An apparatus, comprising: a combustion pre-chamber device for
engaging a cylinder head of an internal combustion engine, the
combustion pre-chamber device including a body with an outer
surface extending between a first end and an opposite second end of
the body, the first end of the body including an opening to an
inner passage defined by the body for receiving a spark plug, the
second end of the body defining a combustion pre-chamber and at
least one through-hole in communication with the combustion
pre-chamber that opens at the outer surface, the body further
including at least one bore extending from an opening at the outer
surface into the body to a closed end of the at least one bore that
is located within the body of the combustion pre-chamber
device.
2. The apparatus of claim 1, wherein the second end of the body
extends at least partially into a combustion chamber of a cylinder
of the internal combustion engine with the body engaged to the
cylinder head, wherein the plurality of through-holes fluidly
couple the combustion pre-chamber with the combustion chamber of
the cylinder.
3. The apparatus of claim 1, wherein the combustion pre-chamber
device defines a cooling channel in the outer surface and that at
least one bore opens in the cooling channel.
4. The apparatus of claim 3, wherein the at least one bore includes
a plurality of bores that each open in the cooling channel.
5. The apparatus of claim 4, wherein the plurality of bores
includes at least one radial bore that extends into the body along
a longitudinal axis that intersects a central longitudinal axis of
the body of the combustion pre-chamber device, the plurality of
bores further including at least one tangential bore that extends
into the body along a longitudinal axis that does not intersect the
central longitudinal axis.
6. The apparatus of claim 5, wherein the radial bore intersects the
tangential bore.
7. The apparatus of claim 1, wherein the at least one bore includes
at least one radially extending bore extending to a first closed
end and at least one tangentially extending bore extending to a
second closed end.
8. The apparatus of claim 7, wherein the radially extending bore
and the tangentially extending bore intersect one another at or
adjacent the first and second closed ends.
9. The apparatus of claim 8, wherein the at least one radially
extending bore includes a plurality of radially extending bores and
the at least one tangentially extending bore includes a plurality
of tangentially extending bores that intersect respective ones of
the plurality of radially extending bores.
10. The apparatus of claim 9, wherein the combustion pre-chamber
device defines a cooling channel in the outer surface and each of
the plurality of radially extending bores and each of the plurality
of tangentially extending bores open in the cooling channel.
11. The apparatus of claim 10, wherein each of the plurality of
radially extending bores and each of the plurality of tangentially
extending bores extend distally from respective opening in the
cooling channel into the body toward a distal end wall of the
body.
12. The apparatus of claim 11, wherein the plurality of
through-holes includes at least one tip through-hole that extends
through the distal end wall and at least one circumferential
through-hole that is proximal of the distal end wall.
13. An apparatus, comprising: a body including a first end defining
an inner passage along a first inner surface of the body at the
first end, the inner passage including threads operable to receive
a plurality of complementary spark plug threads defined by a spark
plug; and the body including a second end opposite the first end
positionable into a combustion chamber of a cylinder, the second
end defining a combustion pre-chamber along a second inner surface
of the body and a plurality of second end threads along an outer
surface of the second end operable to couple to a plurality of
complementary cylinder head threads defined by the cylinder head,
wherein the second end includes at least one through-hole operable
to fluidly couple the combustion pre-chamber and the combustion
chamber of the cylinder, and the body includes at least one first
bore and at least one second bore that intersects the at least one
first bore, the at least one first and second bores each extend
into the body from an opening at the outer surface to a blind end
thereof that is located within the body.
14. The apparatus of claim 13, wherein the at least one first bore
extends radially into the body toward a central longitudinal axis
of the body and the at least one second bore extends tangentially
relative to the central longitudinal axis into the body.
15. The apparatus of claim 14, wherein the at least one first bore
includes a plurality of radially extending bore and the at least
one second bore includes a plurality of tangentially extending
bores that intersect respective ones of the plurality of radially
extending bores.
16. The apparatus of claim 13, wherein the body defines a cooling
channel in the outer surface and the opening of each of the at
least one first bore and the at least one second bore is in the
cooling channel.
17. A system comprising: an internal combustion engine including a
cylinder defining a combustion chamber; a cylinder head engaged to
the internal combustion engine, the cylinder head including a spark
plug passage and a head cooling passage; and a combustion
pre-chamber device positioned in the spark plug passage and coupled
to the cylinder head, the combustion pre-chamber device including a
first end and a second end and having an inner surface and an outer
surface, the inner surface defining a combustion pre-chamber in
fluid communication with the combustion chamber, the outer surface
defining a cooling channel about the combustion pre-chamber device
for receiving a coolant flow from the head cooling passage, the
combustion pre-chamber device further including at least one bore
opening at the cooling channel, the at least one bore extending to
a blind end location within the combustion pre-chamber device, the
at least one bore receiving the coolant flow to provide cooling of
the combustion pre-chamber.
18. The system of claim 17, wherein the at least one bore includes
a first radially extending bore and a second tangentially extending
bore that intersects the first radially extending bore, the coolant
flowing through the first and second bores.
19. The system of claim 18, further comprising a spark plug engaged
in the combustion pre-chamber device, the spark plug including at
least one electrode in fluid communication with the combustion
pre-chamber.
20. The system of claim 18, wherein the second end of the
combustion pre-chamber device includes a distal end wall in the
combustion chamber and at least one through-hole that extends
through the distal end wall.
Description
TECHNICAL FIELD
The present application relates to internal combustion engines, and
more particularly, but not exclusively relates to a combustion
pre-chamber device for spark ignition engines.
BACKGROUND
Combustion pre-chamber devices in spark ignition engines reduce
engine emissions and can improve performance by reducing the timing
delay and increasing the speed of heat release. However, currently
available combustion pre-chamber devices suffer from issues
relating to misfire events and lowered durability of ignition
systems due to the high temperatures within the combustion
pre-chamber devices. Accordingly, there is a continuing demand for
further contributions in this area of technology.
SUMMARY
One embodiment of the present application is a combustion
pre-chamber device for a spark ignition internal combustion engine.
The pre-chamber device includes a number of bores that open at an
outer surface thereof that extend into the body and receive a
coolant flow to provide cooling for a combustion pre-chamber of the
combustion pre-chamber device.
Other embodiments include unique methods, systems, devices, and
apparatus involving or relating to spark ignition engine
modifications and/or emissions control. Further objects, forms,
embodiments, benefits, advantages, features, and aspects of the
present application shall become apparent from the description and
drawings contained herein.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic illustration of a cutaway view of an internal
combustion engine including a combustion pre-chamber device
according to one embodiment of the present disclosure.
FIG. 2 is a schematic illustration of a cross-sectional view of the
combustion pre-chamber device shown in FIG. 1.
FIG. 3 is a schematic illustration of a side view of the combustion
pre-chamber device of FIG. 1 with a partial cutaway at the tip
area.
FIG. 4 is a schematic illustration of a cross-sectional view of a
cylinder head with a spark plug and another embodiment combustion
pre-chamber device having a primary volume and a secondary
volume.
FIG. 5 is a schematic illustration with a partial cutaway of a
perspective view of another embodiment combustion pre-chamber
device.
FIG. 6 is a schematic three-dimensional illustration with partial
cutaways taken from a side of the combustion pre-chamber device of
FIG. 5 engaged in a cylinder head.
FIG. 7 is a schematic illustration of a three-dimensional view
looking toward a second end (distal tip) of the combustion
pre-chamber device of FIG. 5.
FIG. 8 is a schematic illustration of a three-dimensional view from
a side of the combustion pre-chamber device of FIG. 5.
DETAILED DESCRIPTION
For the purposes of promoting an understanding of the principles of
the invention, reference will now be made to the embodiments
illustrated in the figures and specific language will be used to
describe the same. It will nevertheless be understood that no
limitation of the scope of the invention is thereby intended, such
alterations and further modifications in the illustrated
embodiments, and such further applications of the principles of the
invention as illustrated therein being contemplated as would
normally occur to one skilled in the art to which the invention
relates.
FIG. 1 is a cutaway schematic illustration of an internal
combustion engine 100 including a combustion pre-chamber device
118. The engine 100 includes a cylinder head 104 defining a spark
plug passage 106 and a head cooling passage 108. The engine 100
further includes an engine block 110 that assembles with the
cylinder head 104 to form combustion chamber 114 of the engine 100.
A piston 116 is typically provided in combustion chamber 114. In
certain embodiments, the engine 100 is fueled with gasoline, and/or
natural gas and/or related hydrocarbons such as methane, ethane, or
propane. In certain embodiments, the engine 100 is partially fueled
with natural gas, and/or is a hybrid engine using natural gas in
combination with other fuels.
The cylinder head 104 may include multiple spark plug passages 106
corresponding to each of a set of multiple cylinders in the engine
block 110. The spark plug passage 106 receives a spark plug 112
that ordinarily exposes the spark plug electrode to the combustion
chamber 114 defined by the engine block 110. A combustion
pre-chamber device 118 is positioned in the spark plug passage 106
such that the spark plug electrode is not exposed directly to the
combustion chamber 114. In certain embodiments, the combustion
pre-chamber device 118 is a separate device that is coupled to the
cylinder head 104. In certain other embodiments, the combustion
pre-chamber device 118 is formed integrally with the cylinder head
104.
Referring to FIG. 2, combustion pre-chamber device 118 is
illustrated in isolation. The device 118 includes a body 201 that
extends from a first (proximal) end 202 to a second (distal) end
204. In certain embodiments, the first end 202 and the second end
204 are formed independently and secured together to form body 201.
In certain other embodiments, the first end 202 and the second end
204 are formed as a single unit to provide an integral body 201.
The device 118 further includes an inner surface including a first
inner surface portion 206a and a second inner surface portion 206b,
and an outer surface 208. In certain embodiments, the outer surface
208 defines a cooling channel 210 about the outer surface 208 of
device 118. The cooling channel 210 is fluidly coupled to the head
cooling passage 108 in cylinder head 104. In certain embodiments,
the cooling channel 210 is a channel defined by the outer surface
208 and cooperates with the spark plug passage 106 and the cylinder
head 104 to define a cooling jacket around the body 201 of device
118.
The first end 202 of body 201 defines an inner spark plug passage
224 along the first inner surface 206A, the inner spark plug
passage 224 defining threads 212 that receive complementary spark
plug threads defined by spark plug 112. In certain embodiments, the
inner surface 206a at the first end 202 of body 201 includes first
end threads 212 that are threadingly engageable to the threads of
spark plug 112. In certain embodiments, the second end 204 of body
201 opposite the first end 202 includes second end threads 226
along the outer surface 208 that couple to complementary threads on
the cylinder head 104. In certain embodiments, the threads on the
cylinder head 104 are the original threads intended for the spark
plug 112. In certain embodiments, the threads on the cylinder head
104 are threads machined on the cylinder head 104 formed by tapping
a larger hole in the cylinder head 104 such that the device 118
engages a larger diameter hole than originally placed in the
cylinder head 104 for the spark plug 112. In certain embodiments,
the cylinder head 104 may be formed with a larger diameter hole
structured to receive a combustion pre-chamber device 118, and/or
the cylinder head 104 may be formed integrally with a combustion
pre-chamber device 118.
The second end 204 of body 201 includes a distal tip that is
substantially enclosed with a distal end wall 220 that includes a
fluid connection with the inner passage 224 at first end 202.
Distal end wall 220 includes a plurality of through-holes 214, 216
for communication with the combustion chamber 114. Second end 204
defines a combustion pre-chamber 218. The combustion pre-chamber
218 is configured to fluidly communicate with an electrode of the
spark plug 112 when the spark plug 112 is received at the first end
202. In certain embodiments, the spark plug 112 includes multiple
ignition sites, or electrodes, that are in fluid communication with
combustion pre-chamber 218.
While the device 118 is coupled to the cylinder head 104 and the
cylinder head 104 is coupled to the engine block 110, the second
end 204 extends into the cylinder combustion chamber 114. The
distal end wall 220 of second end 204 is located in the cylinder
combustion chamber 114 sufficiently such that the through-holes
214, 216 communicate with the cylinder combustion chamber 114 to
receive the charge air and fuel without interfering with the piston
116.
In certain embodiments, the second end 204 includes a plurality of
circumferential through-holes 214 that are positioned around distal
end wall 220 at the circumference of the second end 204, but do not
extend through distal end wall 220. The first through-holes 214
provide fluid coupling between the combustion pre-chamber 218 and
the cylinder combustion chamber 114. In certain further
embodiments, the second end 204 includes at least one tip
through-hole 216 near a center of the distal end wall 220. The tip
through-hole(s) 216 may be at the center of the distal end wall 220
or near the center of the distal end wall 220. In certain
embodiments, the spark plug 112, the spark plug passage 106, and
the combustion pre-chamber device 118 may share a common central
longitudinal axis 222. The tip through-hole(s) 216 may be aligned
with the central longitudinal axis 222, or may be aligned at an
angle oblique to the central longitudinal axis 222. In certain
embodiments, the tip through-hole(s) 216 are formed near a location
on the distal end wall 220 that is expected to experience the
highest temperatures, for example near the center of the combustion
chamber 114. In certain embodiments, the distal end wall 220
includes at least two tip through-holes 216 defined along axes
parallel to and near the central longitudinal axis 222.
At least one cylindrically-shaped, elongated bore 300 is formed
within the body 201. An exemplary representation of cross-sectional
view of a bore 300 is shown in FIG. 2. Bore 300 has an outer end
opening 302 at outer surface 208 of the device 118. In the
illustrated embodiment, outer end opening 302 is located in cooling
channel 210. Bore 300 extends along a longitudinal axis from the
outer end opening 302 to a blind or closed inner end 304 positioned
within the material of the body 201 of the device 118. Bore 300 is
representative of a plurality of bores formed within the body 201
of the device 118 that extend in a first direction and orientation
relative to central longitudinal axis 222. For example, a view of a
second bore 350 is depicted in FIG. 2. As can be understood from
comparing positions of bore 300 and bore 350 as shown in the
cross-sectional view in FIG. 2, the bores 300, 350 extend in a
plurality of different directions within the body 201. The bores
300, 350 provide a heat transfer environment that reduces the
temperature of the distal end wall 220 during combustion, which may
prevent pre-spark detonation of fuel and may improve the
reliability of the combustion pre-chamber device 118.
In an embodiment, each one of the bores 300 has an end opening 302
positioned at a point along the circumference of a circle C
defining an outer boundary or perimeter of the body 201 at the
position of the cooling channel 210. A dotted line C shown in FIG.
2 represents a position of a plane of such a circle in the
illustrated embodiment. As indicated in the configuration shown in
FIG. 2, the line C may be perpendicular to the central longitudinal
axis 222 of the device 118, and accordingly may also represent a
central horizontal axis C of the device 118, in certain
embodiments. The longitudinal axes of at least some of the
plurality of the respective bores, such as bores 300 and 350
represented in FIG. 2, extend at different angles with respect to
the points on the circumference at which their respective open ends
302, 352 are positioned and central longitudinal axis 222. For
example, bores 300 may extend radially from and intersect central
longitudinal axis 222 and bores 350 may be offset from and
tangentially oriented relative to central longitudinal axis 222 so
as to not intersect central longitudinal axis 222.
FIG. 3 is a schematic illustration of a side view of the combustion
pre-chamber device 118 with a partial cutaway view of a distal tip
area of the device. As shown in FIG. 3, the combustion pre-chamber
device 118 has a plurality of bores 300, 350 as described above.
Bores 300, 350 each include an end opening located on a
circumference of a circular or near-circular shape defining the
outer boundary of the body 201 at the position of the cooling
channel 210. Around the circumference of the circle are a series of
outer end openings 302, 352 of respective bores 300, 350. In
another embodiment such as that shown in FIG. 3, a horizontal plane
bisecting the ring-shaped cooling channel 210 need not be
perpendicular to the central longitudinal axis 222 of the device
118. Dotted line C' as shown depicts such a non-perpendicular plane
of the cooling channel 210.
FIG. 4 is a schematic illustration of a cross-sectional view of
spark plug 112 and another embodiment combustion pre-chamber device
118' installed in cylinder head 104. Device 118' is similar to
device 118, but device 118' includes a combustion pre-chamber 218'
that forms a primary volume 502 and a secondary volume 504. The
device 118' includes bores 300 and 350 formed in the body 201 for
receiving a fooling fluid as previously described with respect to
device 118.
The cylinder head 104 includes spark plug channel 106 that may be
fabricated or machined to receive the device 118, 118'. The
cylinder head 104 also includes head cooling passage 108 fluidly
coupled to an enlarged passageway (the spark plug channel 106), for
example by a machined channel 402 between at least a portion of the
head cooling passage 108 and the spark plug channel 106. In certain
embodiments, the combustion pre-chamber device 118, 118' includes
the cooling channel 210 defined by outer surface 208 that
cooperates with the spark plug passage 106 and the cylinder head
cooling passage 108 to define a cooling jacket around the second
end 204 of device 118, 118'. A coolant fluid may be introduced into
the cooling channel 210 from cooling passage 108.
As shown in FIG. 4, the device 118' receives the spark plug 112 in
an installed position such that the electrode 506 of the spark plug
112 is positioned in the combustion pre-chamber 218'. The
combustion pre-chamber 218' of the device 118' may be formed in a
stepped cylindrical shape along its first and second inner surfaces
206a' and 206b', such that the combustion pre-chamber 218' has a
primary volume 502 of a lesser radius than that of the secondary
volume 504. Secondary volume 504 extends around electrode 506 and
primary volume 504 is located distally of electrode 506 within the
combustion pre-chamber 218' when the spark plug 112 is received in
the inner spark plug passage 224 of device 218'. The spark plug 112
ignites an air-fuel mixture in the primary volume 502 of the
combustion pre-chamber 218', and residual ignition gas (e.g.
combustion products) flow into the secondary volume 504 of the
combustion pre-chamber 218' and away from the electrode 506 of the
spark plug 112. The secondary volume 504 clears residual gas and
combustion byproducts from the spark plug gap at the electrode
506.
The spark plug 112 may be replaced periodically, for example on a
maintenance schedule or as part of a repair operation. The
combustion pre-chamber device 118, 118' may be replaced
periodically, for example on a maintenance schedule or as part of a
repair operation. In certain embodiments, the spark plug 112 is
removed and replaced after a first period of time, and the
combustion pre-chamber device 118, 118' is removed and replaced
after a second period of time.
Also shown in FIG. 4 are examples of two bores 300, 350. Bore 350
is shown as a hole in the plane of the cross-section of body 201 of
the device 118', because the longitudinal axis of the bore 350 is
at a different angle and orientation than that of the longitudinal
axis of bore 300 relative to the central longitudinal axis 222 of
the device 118'. For example, bore 300 can be oblique to central
longitudinal axis 222 and also extends in a proximal and distal
direction toward central longitudinal axis 222 so that bore 300 is
radially oriented and the extension of the longitudinal axis of
bore 300 intersects central longitudinal axis 222. Bore 350 is
tangentially oriented to central longitudinal axis 222 and more
parallel or generally parallel to a plane that is orthogonal to
central longitudinal axis 222.
FIG. 5 is a schematic illustration of a perspective view of the
combustion pre-chamber device 118' with a partial cutaway of the
view to show bores 300, 350 within the device 118'. In this view,
exemplary bores 300, 350 are depicted along their respective
longitudinal axes. The end openings 302 and 352 open at cooling
channel 210. The cylindrically-shaped bore 350 extends along a
longitudinal axis in a direction tangential to a circle around
central longitudinal axis 222 to a closed end 354 of the bore 350
positioned distally closer to the distal end wall 220 of the device
118. Thus flow of coolant into the bore 350 from the cooling
channel 210 is channeled toward the closed end 354 and accordingly
toward the direction of the primary volume 502 defined within the
pre-combustion chamber 218' of the device 118'. Similarly, a bore
300 has an open end 302 that is opened to and in fluid connection
with cooling channel 210. Bore 300 extends radially from central
longitudinal axis 222 and intersects bore 350 at or near closed end
314.
As may be appreciated from FIG. 5, the angles of the longitudinal
axes of bores 300 and 350 differ with respect to central
longitudinal axis 222 of the device 118, 118', so that the bores
300, 350 extend into different portions of the body 201. Hence
different portions of the body 201 may receive the cooling effect
of coolant flowing within the respective bores 300, 350. Also,
bores 300 and 350 differ in bore length, i.e., the distance between
their respective open ends 302 and 352 and closed ends 304 and 354.
The differing bore lengths allow for different portions of the body
201 to receive the cooling effect of coolant flowing within the
respective bores. Shorter bores interposed with longer bores
provide cooling effect to a maximum volume of the material forming
the body 201 of the device 118, 118'.
In an embodiment as depicted in FIGS. 4 and 5, the open ends 302,
352 of the bores 300, 350 are formed at respective points along the
circumference of the circular plane defined at line C through
cooling channel 210. In other embodiments, the open ends 302, 352
of the bores 300, 350 are not formed at cooling channel 210, but
instead are formed at other points along the outer surface 208
between the first end 202 and the second end 204 of the body 201 of
the device 118, 118'.
FIG. 6 is a schematic illustration of a three-dimensional view with
partial cutaways taken from a side of the combustion pre-chamber
device 118, 118'. Device 118, 118' is secured in the cylinder head
104 so that distal end wall 220 is positioned in the combustion
chamber 114 and cooling channel 210 is positioned to receive
coolant flow. The coolant flow move through bores 300, 350 so that
coolant flow is moved close to the distal end wall 220. The
connected ones of the radial bores 300 and tangential bores 350
provide flow vectors so coolant flows in one of the bores 300, 350
and out of the connected one of the bores 350, 300. The coolant
flow reduces temperatures of the combustion pre-chamber 218 which
will reduce misfire events and extend the life of device 118,
118'.
FIG. 7 is a schematic illustration of a three-dimensional view
looking toward distal end wall 220 of the combustion pre-chamber
device 118, 118'. FIG. 7 illustrates bores 300, 350 that intersect
and have longitudinal axes extending in different radial and
tangential directions from one another. For example, bore 300 is a
radially extending bore and is configured with its longitudinal
axis extending radially inwardly in a radial direction with respect
to central longitudinal axis 222. Bore 350 is a tangentially
extending bore and is configured with its longitudinal axis
extending tangentially inwardly with respect to central
longitudinal axis 222. The inward and outward movement of coolant
occurs in the different radial and tangential directions afforded
by the orientations of the differently oriented connected bores
300, 350. For example, coolant may move into and out of the
depicted radial bores 300 marked with a dotted line RF along the
direction of the dotted line RF (radial flow in/out). Coolant may
move into and out of the depicted tangential bore 350 marked with a
dotted line TF along the direction of the dotted line TF
(tangential flow in/out). In the illustrated embodiment, there are
provided six radial bores 300 connected to respective ones of six
tangential bores 350, and the bores 300, 350 are provided in an
alternating arrangement around coolant channel 210. Other numbers
of bores 300, 350 and sequencing of bores 300, 350 around device
118, 118' are also contemplated.
FIG. 8 is a schematic illustration of a three-dimensional
perspective view taken from a side of the combustion pre-chamber
device 118, 118'. Similarly to FIG. 7, FIG. 8 shows a plurality of
bores 300, 350. Radial bores 300 having an outer opening end 302
and an inner closed end 304 are interposed between longer
tangential bores 350. Radially extending bores 300 are interposed
between tangentially extending bores 350. Tangentially extending
bores 350 may extend in a plurality of tangential directions
generally directed toward their closed ends 354 located closer to
the primary volume 502 defined within the combustion pre-chamber
218 of the device 118'. It may be appreciated from FIG. 8 that
interposed bores 300, 350 having differing lengths and differing
angles and orientations with respect to the central longitudinal
axis 222 of the device 118, 118' can be arranged to provide a
maximum reach of cooling effect of the coolant present or flowing
in or out of the bores 300, 350 without forming regular bore
patterns that might create natural fracture lines in the body 201
of device 118, 118'.
It is contemplated that the number, types, orientations, diameter,
and other features of the plurality of bores may differ in various
embodiments. It is further contemplated that the bores can have
open ends and/or closed ends that are positioned at a number of
different points relative to the central longitudinal axis 222
between the first end 202 and the second end 204 of the device 118,
118'. The bores can also have differing angles compared to the
central longitudinal axis 222 of the device 118. 118'. The bores
300, 350 are arranged to provide an effective reduction of
combustion pre-chamber temperatures in different positions
throughout the device 118, 118' without defining regular fracture
lines.
As is evident from the figures and text presented above, a variety
of embodiments according to the present invention are contemplated.
For example, the bores 300, 350 may be drilled in the combustion
pre-chamber device 118, 118' in one embodiment. In another
embodiment, the combustion pre-chamber device 118, 118' is
fabricated by three-dimensional printing to includes bores 300, 350
formed in body 201. Any other suitable technique for fabricating
the combustion pre-chamber device 118, 118' is also
contemplated.
According to one aspect of the present disclosure, an apparatus
includes a combustion pre-chamber device for engaging a cylinder
head of an internal combustion engine. The combustion pre-chamber
device includes a body with an outer surface extending between a
first end and an opposite second end of the body. The first end of
the body includes an opening to an inner passage defined by the
body for receiving a spark plug, and the second end of the body
defines a combustion pre-chamber and at least one through-hole in
communication with the combustion pre-chamber that opens at the
outer surface. The body further includes at least one bore
extending from an opening at the outer surface into the body to a
closed end of the at least one bore that is located within the body
of the combustion pre-chamber device.
In one embodiment, the second end of the body extends at least
partially into a combustion chamber of a cylinder of the internal
combustion engine with the body engaged to the cylinder head. The
at least one through-hole fluidly couples the combustion
pre-chamber with the combustion chamber of the cylinder.
In another embodiment, the combustion pre-chamber device defines a
cooling channel in the outer surface and that at least one bore
opens in the cooling channel. In a refinement of this embodiment,
the at least one bore includes a plurality of bores that each open
in the cooling channel. In a further refinement, the plurality of
bores includes at least one radial bore that extends into the body
along a longitudinal axis that intersects a central longitudinal
axis of the body of the combustion pre-chamber device, the
plurality of bores further including at least one tangential bore
that extends into the body along a longitudinal axis that does not
intersect the central longitudinal axis. In yet a further
refinement, the radial bore intersects the tangential bore.
In another embodiment, the at least one bore includes at least one
radially extending bore extending to a first closed end and at
least one tangentially extending bore extending to a second closed
end. In a refinement of this embodiment, the radially extending
bore and the tangentially extending bore intersect one another at
or adjacent the first and second closed ends. In a further
refinement, the at least one radially extending bore includes a
plurality of radially extending bores and the at least one
tangentially extending bore includes a plurality of tangentially
extending bores that intersect respective ones of the plurality of
radially extending bores. In a further refinement, the combustion
pre-chamber device defines a cooling channel in the outer surface
and each of the plurality of radially extending bores and each of
the plurality of tangentially extending bores open in the cooling
channel. In yet a further refinement, each of the plurality of
radially extending bores and each of the plurality of tangentially
extending bores extend distally from respective opening in the
cooling channel into the body toward a distal end wall of the body.
In still a further refinement, the plurality of through-holes
includes at least one tip through-hole that extends through the
distal end wall and at least one circumferential through-hole that
is proximal of the distal end wall.
According to another aspect of the present disclosure, a body
includes a first end defining an inner passage along a first inner
surface of the body at the first end, and the inner passage
includes threads operable to receive a plurality of complementary
spark plug threads defined by a spark plug. The body also includes
a second end opposite the first end positionable into a combustion
chamber of a cylinder. The second end defines a combustion
pre-chamber along a second inner surface of the body and a
plurality of second end threads along an outer surface of the
second end operable to couple to a plurality of complementary
cylinder head threads defined by the cylinder head. The second end
includes at least one through-hole operable to fluidly couple the
combustion pre-chamber and the combustion chamber of the cylinder.
The body also includes at least one first bore and at least one
second bore that intersects the at least one first bore. The at
least one first and second bores each extend into the body from an
opening at the outer surface to a blind end thereof that is located
within the body.
In one embodiment, the at least one first bore extends radially
into the body toward a central longitudinal axis of the body and
the at least one second bore extends tangentially relative to the
central longitudinal axis into the body. In a refinement of this
embodiment, the at least one first bore includes a plurality of
radially extending bore and the at least one second bore includes a
plurality of tangentially extending bores that intersect respective
ones of the plurality of radially extending bores.
In another embodiment, the body defines a cooling channel in the
outer surface. The opening of each of the at least one first bore
and the at least one second bore is in the cooling channel.
According to another aspect of the present disclosure, a system
includes an internal combustion engine that has a cylinder defining
a combustion chamber and a cylinder head engaged to the internal
combustion engine. The cylinder head including a spark plug passage
and a head cooling passage. The system further includes a
combustion pre-chamber device positioned in the spark plug passage
and coupled to the cylinder head. The combustion pre-chamber device
including a first end and a second end and has an inner surface and
an outer surface. The inner surface defines a combustion
pre-chamber in fluid communication with the combustion chamber. The
outer surface defines a cooling channel about the combustion
pre-chamber device for receiving a coolant flow from the head
cooling passage. The combustion pre-chamber device further includes
at least one bore opening at the cooling channel. The at least one
bore extends to a blind end location within the combustion
pre-chamber device, and the at least one bore receives the coolant
flow to provide cooling of the combustion pre-chamber.
In one embodiment, the at least one bore includes a first radially
extending bore and a second tangentially extending bore that
intersects the first radially extending bore, the coolant flowing
through the first and second bores. In a refinement of this
embodiment, a spark plug is provided that is engaged in the
combustion pre-chamber device. The spark plug includes at least one
electrode in fluid communication with the combustion pre-chamber.
In another refinement, the second end of the combustion pre-chamber
device includes a distal end wall in the combustion chamber and at
least one through-hole that extends through the distal end
wall.
While the invention has been illustrated and described in detail in
the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiments have been
shown and described and that all changes and modifications that
come within the spirit of the inventions are desired to be
protected. It should be understood that while the use of words such
as preferable, preferably, preferred or more preferred utilized in
the description above indicate that the feature so described may be
more desirable, it nonetheless may not be necessary and embodiments
lacking the same may be contemplated as within the scope of the
invention, the scope being defined by the claims that follow. In
reading the claims, it is intended that when words such as "a,"
"an," "at least one," or "at least one portion" are used there is
no intention to limit the claim to only one item unless
specifically stated to the contrary in the claim. When the language
"at least a portion" and/or "a portion" is used the item can
include a portion and/or the entire item unless specifically stated
to the contrary.
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